The invention relates to door frames for railway hopper cars. The standard door frames utilized in the construction of railway hopper cars are formed of cast steel, such as shown in U.S. Pat. No. 2,784,679, whether for cars with rectangular center sills or zee type center sills. Such cast frames are not always readily available, however, and require a great deal of specialized heavy equipment and shop space to produce. It is desirable, therefore, to be able to produce door frames of plate steel, or of plate steel and rolled angles, which may be merely joined for fabrication of door frames. Forming door frames in such a manner, however, can create a large number of problems - for instance, it is often difficult to effect proper assembly of the component parts, to effect secure attachment therebetween, to provide complete interchangeability between such frames and cast frames (which is necessary to allow utilization of standard doors, available hopper chutes and door locks), and to keep welding warpage to a minimum.
Prior art attempts to form hopper car door frames from component parts have not been entirely successful. U.S. Pat. No. 2,341,612 suggests assembly of component casts parts, however such an assembly while not requiring massive shop space still has the major problem of requiring the heavy equipment necessary in order to manufacture cast members, and additionally presents problems of having to assemble, cast, and properly align a door closure section with each of the frame component parts in addition to properly fitting the hopper chute, and to provide secure attachment between the component parts. U.S. Pat. No. 2,712,289 has suggested the use of hot pressed plate members for assembly to form a door frame. Such members are difficult to properly locate with respect to each other to form an exactly dimensioned door frame (as is necessary), however, require simultaneous assembly and securement of the door closure surface with the frame members, and do not provide for simple welding points that will still allow secure attachment of the members together to form a strong enough frame. U.S. Pat. No. 2,591,924 in another such prior art device confronted with similar problems. U.S. Pat. No. 2,519,529 alleviates one of the above-mentioned problems by providing a door closure surface that is integral, however such surface is also difficult to properly locate with respect to the frame members and must be secured by riveting, and no provision is suggested for ease of strong assembly of the frame members.
According to the present invention, a door frame assembly is provided that eliminates all the problems inherent in the prior art devices. The invention comprises four door frame members formed of plate steel, or plate steel and rolled angles. The two horizontal members are cut to a standard size, but do not inhibit the location of the vertical members, so that the vertical dimension can be determined precisely in an assembly jig to insure proper dimensioning of the door frame to fit all standard doors, hopper chutes and locks. Each of the four frame components abuts its adjoining components along two flat surfaces so that fillet welds can be effected therebetween, resulting in a strong and secure structure. The warping from welding is also thereby kept to a minimum. The door closure member is formed of bar steel, requiring only a single joint, and the frame members are adapted so that the door closure abuts flat surfaces on the side and top frame members, and is positively located by a lap surface of the bottom frame member. Thus it will be seen that according to the invention, a hopper railway car door frame is provided that has the following advantages:
(1) the components may be formed completely of plate steel or plate steel and rolled angles,
(2) the components may be precisely dimensioned during assembly in an assembly jig,
(3) the components may be assembled without the necessity of completely aligning a door closure surface associated therewith, the door closure surface being an integral member attached to the assembled frame and being readily locatable and properly secureable thereto,
(4) the assembled frame is strong and secure, being welded along two areas at the joints thereof, and
(5) the frame will replace conventional cast door frames, and receive the same doors and door latches. In general a hopper car door frame is provided that is quick and easy to assemble with great precision and sufficient strength.
The primary object of the present invention is to provide an economical hopper car door frame and one that is readily available. These and other objects of the invention will become clear from an inspection of the detailed description of the invention and the appended claims.